Metagrating-enabled Brewster's angle for arbitrary polarized electromagnetic waves and its manipulation.

Brewster effect has attracted extensive interests through microwave to optical regime. However, previous work mainly focused on the cases with single linear polarization. We demonstrate in this paper an equal Brewster's angle for both TE (transverse-electric) and TM (transverse-magnetic) waves. Tunable Brewster effect is furthermore achieved. For practical implementation of this effect, we propose an anisotropic metagrating composed of modified split ring resonators (MSRR) as a proof-of-concept in X-band. Measurement results of the manufactured prototypes validate our method. The proposed metagrating featuring Brewster's angle manipulation potentially paves the way for many applications throughout the spectrum, e.g., angular selectivity.